Hey fellas!

Back again! I am having troubles with my hvac system mode control. It’s the door that opens/closes when selecting from defrost to vents.

I have the service manuals, but was wondering if anyone had experience with their hvac mode sticking and their solution.

The diverter door makes a creaking sound and sometimes gets hung up and doesn’t switch from defrost to the vents. I can usually bang on my dash when the door starting making noise to help it along.

I do not have issues selecting from defrost to feet, that door or mechanism is working fine.

Can a guy sneak in to grease the door mechanism without taking out the whole dash?

Thanks J30 friends!

Same thing happened on my 93 J30 , A/C would always want to go back to a default position and not stay in upper vents only position ( AZ heat here) , and the little motor began to creak noise getting back into vent mode until it couldn't make it any more - stayed in floor outlet like for heat.

The little motor is waaay back under dash like 3 "left of back or radio , and 20" "IN".Removed valance panel , HVAC ctrl box , ducting , and couple of screws I believe hold it to the left side of the HVAC housing cluster. Beware there is a look alike other little motor you may confuse with. I went to pick-part first to DESTROY a car that was not mine (DACTWNM) and remove one , and learned how to get to it !!

What I found out was I could dismantle the little motor and found gears made up of two different kinds of plastic , where a main gear shaft sort of EXPANDS in hotter weather and I just 1000grit sanded shaft and honed out the hole it went in and used BEAUCOUP Lithium grease and topped all the little gears with Silicone spray , put it back together , installed , lot of work Never utilized the j-yard motor cause the white 'arm-actuator' was a little different and would have to be R&R-ed I declined to do that.

It worked out perfect , as good as new , BUT ONE HELLAVA JOB to do.